DESCRIPTION (Scanned from the applicant's description): This program seeks to develop a transdermal system capable of delivering 1,500 ug of levonorgestrel over the course of 24 hours through two 30 cm2 patches. Such a system should be as effective for emergency contraception as the currently approved oral method, while offering greater convenience and fewer side effects. Although the required transdermal dose is high for a drug as insoluble as levonorgestrel, BIOTEK's past experience suggested that it could be achieved. Phase I began with an in vitro study on human skin to confirm and optimize high levonorgestrel fluxes, continued with a study of irritation and bioavailability in rabbits, and concluded with an evaluation of materials for use in comfortable patches capable of maintaining good skin contact over a large area. These tasks were successfully completed. The Phase II work proposed here will complete patch design work, prepare and characterize GMP patches, submit an IND, and conclude with a 10-subject human clinical dose ranging study of safety, follicular response, and levonorgestrel pharmacokinetics at the Jones Institute of the Eastern Virginia Medical School. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE